Methods for isolating, purifying, and concentrating biological materials are known and include, for example, chromatography, ultrafiltration, and lyophilization, see generally, R. Hatti-Kaul et al., “Downstream Processing in Biotechnology,” in Basic Biotechnology, Chap. 9, pages 187-211, 2nd ed., Cambridge University Press (2001). Processes for making concentrated monoclonal antibody preparations for administration to humans are known, see for example, U.S. Pat. No. 6,252,055, which uses ultrafiltration and which re-circulates the resulting filtrate.
Some challenges associated with available antibody concentration methods include, for example, low fluxes, long process times, large membrane areas, mechanical recovery yield and losses, operator-intensive intervention or handling, low mass transfer rates, energy inefficiencies, and hydraulic pressure limits on concentration equipment. These and other challenges can contribute to a high total cost of manufacture and ultimately higher costs to therapeutic drug consumers.
There is a need for improved processes for preparing highly concentrated protein formulations, such as liquid antibody preparations and therapeutic products thereof.